Fig. 9

Curves of \(\langle x \rangle\) in modified HR with HB. Averaged x curves, \(\langle x \rangle\), (thick solid) correspond to \(I = -0.8, 2.8\), and 5.8, increasing from the left. z-nullclines (dotted) correspond to =20 (steeper) and 60. Other parameters as in Fig. 8